And I'm Robert Siegel. This week, we're posing this question: How have the lessons learned from past U.S. interventions, or non-interventions, informed the discussion of intervening directly, or indirectly, in Syria? Today, we'll hear about the lessons of Iraq and Afghanistan from someone who was ambassador to both those countries. Ryan Crocker, who's now a fellow at the Jackson Institute for Global Affairs at Yale University, was also ambassador to Syria and Lebanon, too. And he joins us now; welcome to the program.

RYAN CROCKER: Thank you, Robert. It's a pleasure to be on.

SIEGEL: Ambassador Crocker, a civil war is threatening the very unity of that country, sending huge refugee populations out across its borders; drawing regional powers in through surrogates, mostly. How do the two big U.S. military engagements of this century influence the debate over what Washington should do about Syria?

CROCKER: I think what we're seeing is a great deal of caution on the part of the administration. I think that caution is well-placed, given the conditions and circumstances in Syria. I think every situation has to be studied in its own terms. Syria is not Iraq. It's not Afghanistan. But some of the difficulties we encountered in both of those countries that we did not foresee, I think, are adding to a sense of caution.

SIEGEL: Well, let's say we were in the room somewhere, discussing this in the administration. What would be the most disappointing experiences that would say don't do it again; don't do what we did in Iraq?

CROCKER: The lesson I've absorbed from it is, be careful what you get into. You know, be sure you really understand the dynamics of a country where you're contemplating an intervention. Have people who know its language, its political culture, its history, how its history is perceived by its own people. In other words, don't go in blind. And arguably, we pretty much did that in Iraq, and paid for it.

SIEGEL: What role does the atrocious behavior of the dictator play in a discussion like this; that is, when one says 70,000 people have been killed already, and inaction by the world community could kill another several tens of thousands over the next year or two, how does one deal with that discussion?

CROCKER: It is a terrible thing, you know. The tens of thousands of his own citizens that Bashar al-Assad is responsible for killing, I think, horrify any civilized person. But the question you have to ask is, can intervention make it better, or could it make it worse? And I think there's a pretty strong current running right now; that there are no good options for intervention that are going to bring peace, remove the government, and stop the killing.

SIEGEL: There was a time after the first Iraq War during which the U.S. had urged Kurds in the north of Iraq, and Shiite Muslims in the south, to rise up against Saddam Hussein. And they belatedly did, I guess. Saddam Hussein appeared to be on the way to crushing those groups, and we and our allies imposed no-fly zones in the north and south of the country. Can that be invoked as a parallel to what's happening here; and do something that's short of full intervention, but more than even arming groups that are fighting in the war?

CROCKER: The Syrian regime, I would argue, has been preparing for what's happening now for at least 30 years - ever since the massacre at Hama in 1982, when Hafez al-Assad's forces surrounded and destroyed the old city to eliminate the Muslim Brotherhood, killing thousands of innocent people in the process. So I think Assad - father and son - knew that there could be a day of reckoning, and they have organized their security, intelligence and defense apparatuses to be ready for it.

I make this point because I think Syrian air defenses are going to be considerably more formidable than what Iraq had, which was almost nothing by the time we got done with Desert Storm. And we have to ask ourselves the questions, are we prepared to lose planes, and pilots, to eliminate all of Assad's air defenses and if we do that, is it really going to stop the killing?

SIEGEL: Of course, advocates of a no-fly zone could point to recent Israeli strikes, and say the air defenses of Syria don't seem to be so impervious to them. They've staged a couple of airstrikes on targets that they say would have assisted Hezbollah in Lebanon.

CROCKER: My sense of it is that there are a number of things you can do once. But an effort to eliminate the entire Syrian air defense system would require repeated strikes in pretty close succession. That is a lot more dangerous than, you know, a one-off strike every month or so.

SIEGEL: You've been ambassador to countries that have had at least authoritarian leaders; sometimes, outright despotic leaders. Do you detect - is it a media impatience, or a political impatience, with the idea of tolerating somebody who might be an utterly unpleasant leader, but he's there and it beats our going to war?

CROCKER: It's a profound question. In some of the commentary, I've seen the point raised - you know, if we just didn't have that injunction against assassination, maybe there would be a way to get the worst people in the world out of government without going to a full-scale conflict. But that's something else that will have to be thrashed out in Washington. It's just a very, very big issue to decide you're going to invade and occupy a country, to remove that leader.

SIEGEL: But can one be measured and say no, we're not going to do that, but we are going to back this rebel force. And there'll be a line beyond which we won't go; if they lose, they lose.

CROCKER: If we know what that rebel force actually is - how strong is it; what's its agenda; who else is backing it? I don't think we want to be in the business of providing material support, particularly lethal material support, to a group that may be passing it on to al-Qaida. And I just return to my point - our level of knowledge is pretty modest, at this point.

SIEGEL: Do you assume that we do not even have - as I've heard it said - sneakers on the ground; people in there, making a first-hand intelligence assessment of what's going on in Syria?

CROCKER: We may. What I would argue that we need is not sneakers on the ground but wingtips on the ground, you know, a small number of Foreign Service officers who are familiar with the region who speak Arabic. I think you would get far more volunteers, and it would be safe to send. But the most critical diplomacy is done in the hardest places. We need more than just intelligence.

We need analysis. We need recommendations. We need the kind of influence that can only come if you've got diplomats on the ground. And I am just afraid that Benghazi has put us into a bunker mode where it's zero risk. And zero risk means you're not doing diplomacy where you need it the most.

SIEGEL: Ambassador Crocker, former - retired Ambassador Ryan Crocker, thank you very much for talking with us today.

CROCKER: Thank you, Robert. It's a pleasure.

SIEGEL: Ambassador Croker is now at Yale University, and he spoke to us from New Haven, Connecticut. Transcript provided by NPR, Copyright NPR.